Romney is an Anglo-Norman name, not Anglo-Saxon. The Romneys came to England after the Norman Conquest, which ended the Anglo-Saxon era. Mitt Romney's basic family tree involves three other families, the Pratts, the Wilckens, and the Lefounts. The Pratts are Anglo-Saxon, the Wilckens are German, and the Lefounts are French. Only a portion of Romney's family tree is Anglo-Saxon - ie mostly the Pratt family line. It sounds like an interesting family history.
Obama's father is Kenyan. That's half of his family tree.
His mother's name was Dunham, which is ancient Anglo-Saxon. You can trace her line of male heritage (ie the Dunham name) back to Plymouth, Mass, and then Deacon John Dunham Sr in Nottingham, England.
Sheesh.